The goal of this study is to estimate the rate of progression to threshold retinopathy of prematurity (ROP) in infants breathing room air whose oxygen saturation values are too high to be eligible for supplemental therapeutic oxygen vs. oxygen for treatment of prethreshold retinopathy of prematurity (STOP-ROP). We are still open for enrollment of subjects in this study. DSMC recommended continuing enrollment until March 31, 1999.